Oil and gas drilling rigs are located throughout the world and require high power to be supplied to the major machinery on the rigs. The rigs used for drilling to land based fossil reserves are typically smaller than those used on offshore rigs and are designed to be easily disassembled and loaded onto trucks for transport to alternate locations. Offshore rigs are larger and can be moved completely to a new location. This distinction in operating practice necessitates the use of connectors on land drilling rigs for easy strip down and allows for hard wiring on the rigs built for offshore applications.
The field assembly and installation of many inland drilling rigs has led to the widespread use of single pole electrical connectors capable of safely connecting the load supply to high powered electrical motors used on the rigs. A typical connector used in this service is the R49 series connector. This connector is designed to carry a typical supply of 1000 v and 1000 amps. Requirements for a R49 series connector include that the operator is fully protected from the dangerous supply, that it can be locked in the mated condition when in service, that it remains unaffected by harsh environmental conditions experienced, that it can be easily and safely disconnected when required, and that it must be robust and be capable of withstanding significant rough handling in the field. An exemplary R49 series connector is disclosed in U.S. Pat. No. 8,961,205 to Graeme Sandwith, the contents of which are incorporated herein by reference.
Due to the heavy nature of the high power cables used for such major machinery, a need exists for adequate strain relief for the cables to prevent the cables from separating from the connectors and potentially exposing operators to the energized power conductors.